package com.example.day05;

public interface Shape {

    public abstract double getParameter();
    public abstract double getArea();
}

class Circle implements Shape {

    private double radius;

    public Circle(double radius) {
        this.radius = radius;
    }

    @Override
    public double getParameter() {
        return 2 * Math.PI * radius;
    }

    @Override
    public double getArea() {
        return Math.PI * radius * radius;
    }

    public static void main(String[] args) {
//        Circle c = new Circle(1.23);
        Shape c = new Circle(1.23); // ***
        System.out.println(c.getParameter());  //
        System.out.println(c.getArea());
    }
}